Unless you bought a family plot, they could be buried wherever. Plots could be bought, where I am researching, in depths of 1, 2 or 3 for the number of coffins. In poorer, urban areas, coffin depths could be 9 or 10 and all mixed up. Family had to pay for you to be burried. For those with no money, or relative, there were 'pauper-graves'.